Brush mechanism for dynamo-electric machines



. a v c. 11. M NEHL 9 BRUSH MECHANISM FOR DYNAMO ELECTRIC MACHINES FiledApril 29 1932 2 Sheets-Sheet 1 Ti l INVENTOR. Kym/.55 [M -"NEIL BY jmfl.

M ATTORNEY m 9 35 C. H. MCNEHL mm BRUSH MECHANISM FOR DYNAMO ELECTRICMACHINES Filed April 29, 1932 2 Sheets-Sheet 2 i E j .4 i 1 T g 3 Q 7 j33 d g I 4'? v 35 mm 1N VEN ATTORNEY Patented Oct. 1, 1935 PATENT OFFICEBRUSH MECHANISM FOR DYNAMO- ELECTRIC MACHINES Charles I. McNeil,Bloomfield, N. J., assignor, by

mesne assignments, to Eclipse Aviation Corporation, East Orange, N. J.,a corporation of New Jersey Application April 29, 1932, Serial No.608,304

33 Claims.

This invention relates to dynamo-electric machines, and moreparticularly to brush. mecha nism for such machines.

One of the objects of the present invention is to provide, for machinesof the above character,

- novel brush mechanism for operatively connecting the machine to anelectric circuit and for interrupting the flow of current between saidmachine and circuit.

Another object of the invention is to provide novel brush-liftingmechanism for a dynamoelectric machine, said mechanism being soconstituted that the brushes of the machine may be moved frominoperative to operative position in such a manner as to avoid damage tothe commutator, or collector rings, associated with said brushes.

Another object is to provide a novel brushliiting mechanism adapted tobe controlled from a point remote from the dynamo-electric machine, saidmechanism being so constructed that the brushes will be brought intocontact with the commutator, or collector rings, without shock or damageto the elements of the machine.

Still another object is to provide a brush mechanism of the above typeembodying a novel brush holder so constructed and arranged that thebrushes are resiliently carried thereby to aid in preventing shock ordamage thereto and to the commutator or slip ring with which the brushesare associated, and also to facilitate the replacement of the brusheswhen necessary.

The above and other objects and advantages of the invention will appearmore fully hereinafter from a consideration of the detailed descriptionand the accompanying drawings illustrating one embodiment of theinvention. It is to be expressly understood, however, that the drawingsare for the purpose of illustration only and are not designed as adefinition of the limits of the invention, reference being had primarilyfor this purpose to the appended claims.

In the drawings wherein like reference characters refer to like partsthroughout the several views:

Fig. l is a partial longitudinal section of a dynamo-electric machineembodying the present invention;

Fig. 2 is a top plan view, with parts broken away and partly in section,illustrating the mechanism shown in Fig. 1;

Fig. 3 is a transverse half section taken on lines 3-3 of Fig. 2;

Figs. 3a and 3b are detail perspective views of one form of novel brushholder used in the apparatus embodying the present invention; and

Fig. 4 is a detail elevation of one of the brushes showing theproportions thereof.

In the form shown, the novel brush mechanism of the present invention isoperatively associated 5 with a dynamo-electric machine having a casingiii, a field winding H, a rotor 52 and a com.- mutator, or slip ring 23.These elements of the structure may be of any suitable type and per seconstitute no part of the present invention. Casing it is provided withan end section i i which encloses the commutator, or slip ring, and thenovel brush mechanism.

Referring more particularly to Figs. 2 and 3, it will be noted thatsection i4 carries a pair of insulating members 65 that are preferablyformed of bakelite or similar material and are removably secured to theinner surface of said casing section as by means of screws i6. Attachedin any convenient manner, as by means of rivets ll, to each insulatingmember i5 is a current-carrying bracketl8 having an inwardly extendingear to which receives a binding post l9 (Fig. 3) for an electricalconductor to. In the form shown, bracket i8 is laterally spaced frommember l5 by means of washers 2! which may be formed of mica or othersuitable material.

The inner end of each bracket 68 is provided with a pivot pin or rod 22on which is pivotally mounted an arm 23 to the outer end of which isremovably and resiliently attached a brush 2A. In the illustratedembodiment and more particularly as shown in Figs. 3a and 3b, arm 23 isprovided with a tab which is bent up to form a sleeve 25 in which thebrush 2% is carried, the brush being held in an operative position inthe sleeve by means of a leaf spring 26 that is pivotally secured at Etato the top of, and extends beyond the outer end of, the arm 23. Theouter end of spring 2%; passes over the top of the brush 24 and isseated in a recess :Z'l formed therein, whereby the brush is yieldinglyand removably held in operative position on the arm. The brush 24 hasits upper portion enlarged, as shown in Fig. 4, in order to prevent itfrom slipping through the sleeve 25. It will be seen that when it isdesired to replace the brush 24, the outer end of the leaf spring 26 ismanually lifted out of the recess 21 of the brush and swings to the leftor right on the pivot Eta thereby clearing the brush to permit readyremoval thereof. After the brush is replaced, the outer end of the leafspring 26 is lifted and moved angularly on its pivot toward the centerof the brush and then the spring is 5 released, whereupon the brushbecomes automatically locked in the holder 25 by virtue of the seatingof the end of the spring in the recess 21 of the brush. Casing section14 is preferably provided with openings I4aadjacent the brushes in orderto facilitate inspection and replacement of the latter.

Means are provided for normally holding the brushes in raised orinoperative position and, as is well understood in the art, when saidbrushes are thus held, the dynamo-electric machine (a generator in theillustrated embodiment) is disconnected from its associated circuit. Forthis purpose, each arm has associated therewith a spring 28 which iswound around the pivot pin 22, one end of said spring having engagementwith the lower surface of arm 23 while the other end of the spring bearsagainst a stop 29 which projects laterally from bracket I8 immediatelybelow the pivot pin. It will thus be seen that spring 28 tends at alltimes to hold brush 24 in inoperative position out of engagement withthe commutator I3 if the invention is employed in a direct currentmachine.

Means are provided for moving the brushes to operative position againstthe tension of springs 28, and are so constructed that the brushes areyieldingly moved into engagement with the commutator in such a manner asto avoid damage to the latter. In the form shown, said means include asolenoid 30 embodying a casing 31, a winding or coil 32 and bindingposts 33 adapted to be connected to a suitable source of current, theenergization of said coil 32, by said source of current, beingcontrolled by a suitable switch (not shown). In most installations, theswitch will be located at a distance remote from solenoid 30. The latteralso embodies a plunger constituted by a movable armature 34 to which issecured a rod 35 having an enlarged head 36. The rod or plunger 35 issupported within the solenoid in any suitable manner asby means of abracket or projecting finger 33w carried by the frame I4.

In the illustrated embodiment, the solenoid is fixedly secured to casingsection I4 of the generator by means of a bracket 31 provided withsuitable openings 38 to receive screws 39. To insure water-tightness,the bracket 39 carries a cover plate 40 removably attached to saidbracket as by means of bolts 4|. The casing or housing 3| of thesolenoid may be welded or secured in any suitable manner to cover plate40. As shown more clearly in Fig. 3 plunger 34, 35 is disposed radiallyof the substantially cylindrical casing l0, l4 and is surrounded by asleeve 42 which is located centrally of coil 32 and. extends throughcasing 3|, cover plate 40, bracket 31 and into an opening provided inthe casing section. I4.

Surrounding rod 35 and longitudinally movable with respect thereto is asleeve 43 which is preferably formed of bakelite, or other suitableinsulating material, and which is provided with an enlarged chamber 44adjacent the lower end thereof. A coil spring 45 is positioned inchamber 44 and surrounds rod 35, the lower end of the spring restingagainst head 36 of said rod and the upper end of the spring bearingagainst the annular shoulder formed by the upper wall of chamber 44.Spring 45 yieldingly holds sleeve 43 in a predetermined positionlongitudinally of rod 35. The lower end of sleeve 43 is enlarged to forman annular shoulder 46 which projects beneath and is engaged by theinner ends of arms 23, said arms being yieldingly held in engagementwith said shoulder 46 by springs 28 and 45. It will thus be seen thatsprings 28 act through arms 23 to resist upward movement of sleeve 43and, through spring 45, the upward movement of plunger 34, 35.

In operation, the switch (not shown) is closed to energize coil 32,whereupon plunger 34, 35 is moved outwardly relative to casing sectionl4. The movement of the plunger is yieldingly transmitted through spring45 to sleeve 43, 45, whereby the latter is moved upwardly and the innerends of arms 23 are swung upwardly against the tension of springs 28.The swinging movement of the inner ends of arms 23 is effective to movebrushes 24 into engagement with the commutator (or slip ring). Due tothe yielding connection which includes sleeve 43 and spring 45, and alsodue to the action of the leaf spring 26, brushes 24 are yieldingly movedinto engagement with the commutator whereby damage to the latter, suchas scoring, is prevented. When it is desired to disconnect thedynamo-electric machine from its associated circuit (not shown), thecontrol switch, referred to above, is opened whereupon coil 32 isde-energized and springs 28 and 45 are effective to return the parts tothe inoperative position illustrated in Fig. 3.

There is thus provided a novel brush mecha nism which is so constructedthat the brushes may be moved from inoperative to operative positionwithout damage to the parts of the machine, the control being located ata distance from the machine if desired. The sharp, positive movementresulting from direct solenoid action on brush-carrying. arms is avoidedand the flow of current between the dynamo-electric machine and itsassociated circuit is readily controlled. There is also provided a novelbrush holder whereby the operation of the entire mechanism is renderedmore efficient.

The mechanism is particularly adapted for use as a cut-out for the highvoltage side of multicurrent, engine-driven radio generators such as areextensively employed on aircraft. As will be understood by those skilledin the art, however, the present invention is not limited to such useand may be advantageously employed in various types of dynamo-electricmachines due to its ready installation and dependable operation. Variouschanges may be made in the details of construction and arrangements ofparts without departing from the invention. Accordingly, reference willbe had primarily to the appended claims for a definition of the limitsof the invention.

What is claimed is:

1. In apparatus of the class described, a brush, a pivotally mounted armcarrying said brush, resilient means operatively engaging the arm forholding the brush in inoperative position, a sleeve having a portionthereof engaging said arm, a solenoid having a core, and resilient meansinterposed between said core and sleeve, said solenoid being adapted toraise said sleeve whereby said brush is moved to operative position.

2. In a generator of the commutator type, a plurality of brushes,spring-pressed arms for normally holding said brushes out of engagementwith the commutator, a solenoid having a movable plunger, and meansincluding a sleeve surrounding said plunger, said sleeve having anenlarged head engaging each of said arms, and said solenoid beingoperative through said means to move said brushes into engagement withthe commutator.

3. In a generator of the commutator type, a plurality of pivotallymounted arms, brushes carried by said arms for engagement with thecommutator, resilient means operatively connected to said arms, asolenoid having a movable plunger, a sleeve surrounding said plunger andhaving an enlarged portion adapted to engage said arms, and a coilspring interposed between said sleeve and plunger for transmittingmovement of the plunger to said sleeve.

4. In apparatus of the class described, a pivotally mounted arm, a brushremovably secured to one end of said arm, a sleeve having an enlargedportion engaging the other end of said arm, a solenoid having a plungerextending through said sleeve, resilient means interposed between saidsleeve and plunger, and resilient means for holding said arm inengagement with the enlarged portion of said sleeve.

5. In a dynamo-electric machine, a substantially cylindrical casing, asolenoid mounted on said casing and having a plunger radially disposedwith respect to the casing, an insulating sleeve surrounding saidplunger, yielding means for normally holding said sleeve in apredetermined position with respect to said plunger, arms engaging saidsleeve, brushes carried by said arms, and yielding means for opposingmovement of the sleeve and plunger in an outward direction relative tothe casing.

mutator type, a brush for the commutator, an

arm carrying said brush, means for yieldingly holding said brush ininoperative position, a solenoid having a core, a yielding connectionbetween said core and said arm for moving said brush to operativeposition, and resilient means pivoted on said arm for holding the brushthereon and for preventing shock to said brush upon its being moved tooperative position.

3. In a dynamo-electric machine, a brushholder, a brush, combinedelectrical and resilient means for moving said brush int o operativeposition, resilient means for opposing said movement of the brush, andanother resilient means pivotally mounted on the brush-ho1der forpreventing shock to the brush upon its being moved into operativeposition.

9. In a brush operating mechanism of the type embodying remotelyoperated means for actuating the brushes into engagement with acooperating commutator of a dynamo-electric machine, the combination ofa brush-holder pivotally mounted for actuation by said actuating meansand comprising an arm having a sleeve at one end thereof into which abrush is adapted to be inserted, a brush in said sleeve and having aportion greater than the sleeve portion to prevent said brush fromslipping through said sleeve and also having a recess therein, and aspring secured to said arm and having one end seated in the recess ofthe brush to hold the latter in the sleeve and to provide resiliencythereto for preventing excessive impact of the brush against thecommutator upon operation of the actuating means.

10. In a brush operating mechanism of the type embodying remotelyoperated means for actuating the brushes into engagement with acooperating commutator of a dynamo-electric machine, the combination ofa brush-holder pivotally mounted for actuation by said actuating meansand comprising an arm having a sleeve at one end thereof into which abrush is adapted to be inserted, a brush in said sleeve and having aportion greater than the sleeve portion to prevent said brush fromslipping through said sleeve and also having a recess therein, a springsecured to said arm and having one end seated in the recess of the brushto hold the latter in the sleeve and to provide resiliency thereto forpreventing excessive impact of the brush against the commutator uponoperation of the actuating means, and means normally maintaining saidbrush-holder in non-engaging position.

11. In a brush operating mechanism of the type embodying remotelyoperated means for actuating the brushes into engagement with acooperating commutator of a dynamo-electric machine, the combination ofa brush-holder pivotally mounted for actuation by said actuating meansand comprising an arm having a sleeve at one end thereof into which abrush is adapted to be inserted, a brush in said sleeve and having aportion greater than the sleeve portion to prevent said brush fromslipping through said sleeve and also having a recess therein, and aspring secured to said arm and having one end seated in the recess ofthe brush to hold the latter in the sleeve and to provide resiliencythereto for preventing excessive impact of the brush against thecommutator upon operation of the actuating means, said spring beingpivoted on said arm so that upon having its end lifted out of the recessin the brush it may be shifted to one side or the other of the sleeve tofacilitate the insertion and removal of the brush.

12. In a brush operating mechanism of the type embodying remotelyoperated means for actuating the brushes into engagement with acooperating commutator of a dynamo-electric machine, the combination ofa brush-holder pivotally mounted for actuation by said actuating meansand comprising an arm having a sleeve at one end thereof into which abrush is adapted to be inserted, a brush in said sleeve and having aportion greater than the sleeve portion to prevent said brush fromslipping through said sleeve and also having a recess therein, a springsecured to said arm and having one end seated in the recess of the brushto hold the latter in the sleeve and to provide resiliency thereto forpreventing excessive impact of the brush against the commutator uponoperation of the actuating means, said spring being pivoted on said armso that upon having its end lifted out of the recess in the brush it maybe shifted to one side or the other of the sleeve to facilitate theinsertion and removal of the brush, and means normally maintaining saidbrush-holder in non-engaging position.

13. In a dynamo-electric machine of the commutator type, a plurality ofbrushes for said commutator, pivotally mounted arms carrying saidbrushes at one end, respectively, and having their opposite endsadjacent each other in relatively close spaced relation, yielding meansfor holding said brushes out of engagement with said commutator, andcombined electrical and yielding means including a member interposedbetween the adjacent ends of said brush arms and engaging the latter formoving said brushes into engagement with the commutator.

14. In a dynamo-electric machine, a plurality of brushes, pivotallymounted arms carrying said brushes at one end, respectively, and havingtheir opposite ends adjacent each other in relatively close spacedrelation, resilient means for holding said brushes in inoperativeposition, and combined electrical and resilient means including a memberinterposed between the adjacent ends of said brush arms and engaging thelatter for opposing said first-named resilient means and for moving saidbrushes to operative position.

15. In a dynamo-electric machine having a commutator, brushes for thecommutator, pivotally mounted arms carrying said brushes at one end,respectively, and having their opposite ends adjacent each other inrelatively close spaced relation, means secured to said brush arms forholding said brushes out of engagement with said commutator, electricalmeans, a member interposed between the adjacent ends of the brush armsand engaging the latter and movable by said electrical means in adirection transverse to said brush arms, and a yielding connectionbetween said electrical means and said member whereby energization ofsaid electrical means is effective through said connection to move saidbrushes to operative position.

16. In a dynamo-electric machine of the commutator type, a pair ofpivotally mounted arms extending in opposite directions from a radialline of the commutator and having their inner ends closely adjacent eachother on either side of said radial line, brushes carried by said armsat the outer ends thereof, resilient means associated with said arms fornormally holding said brushes out of engagement with the commutator, anda member movable along said radial line and engaging the adjacent endsof said brush arms for moving the brushes into engagement with thecommutator.

1'7. In a dynamo-electric machine of the commutator type, a pair ofpivotally mounted arms extending in opposite directions from a radialline of the commutator and having their inner ends closely adjacent eachother on either side of said radial line, brushes carried by said armsat the outer ends thereof, resilient means associated with said arms fornormally holding said brushes out of engagement with the commutator, amember movable along said radial line and engaging the adjacent ends ofsaid brush arms for moving the brushes into engagement with thecommutator, and other resilient means carried by said brush arms andengaging said brushes for holding the latter on said arms and to provide resiliency thereto for preventing excessive impact of said brushesagainst said commutator.

18. In a dynamo-electric machine of the commutator type, a pair ofpivotally mounted arms extending in opposite directions from a radialline of the commutator and having their inner ends closely adjacent eachother on either side of said radial line, brushes carried by said armsat the outer ends thereof, resilient means associated with said arms fornormally holding said brushes out of engagement with the commutator, andelectrical actuating means including a member movable along said radialline and engaging the adjacent ends of said brush arms for moving thebrushes into engagement with said commutator.

19. In a dynamo-electric machine of the commutator type, a pair ofpivotally mounted arms extending in opposite directions from a radialline of the commutator and having their inner ends adjacent each otheron either side of said radial line, brushes carried by said arms at theouter ends thereof, resilient means associated With said arms fornormally holding said brushes out of engagement with the commutator, asolenoid having a plunger movable along said radial line, and a membercarried by said plunger in substantial alignment therewith and engagingthe adjacent ends of said brush arms for moving the brushes intoengagement with the commu tator upon energization of said solenoid.

20. In a dynamo-electric machine of the commutator type, a pair ofpivotally mounted arms extending in opposite directions from a radialline of the commutator and having their inner ends adjacent each otheron either side of said radial line, brushes carried by said arms at theouter ends thereof, resilient means associated with said arms fornormally holding said brushes out of engagement with the commutator, asolenoid having a plunger movable along said radial line, a membercarried by said plunger in substantial alignment therewith and engagingthe adjacent ends of said brush arms for moving the brushes intoengagement with the commutator upon energization of said solenoid, andresilient means between the plunger and the member [or preventing suddenimpact of said brushes against said commutator.

21. In a dynamo-electric machine of the comnri'itator type, a brush forthe commutator, an arm carrying said brush, means for yieldably holdingsaid brush in inoperative position, a solenoid having a plunger operatedthereby in a radial direction with respect to the commutator, and amember carried by said plunger and movable longitudinally therewith andengaging the brush arm whereby said plunger is effective to move saidmember for moving the brush to operative position upon energization ofsaid solenoid.

22. In a dynamo-electric machine of the commutator type, a brush for thecommutator, an arm carrying said brush, means for yieldingly holdingsaid brush in inoperative position, a solenoid having a plunger operatedthereby in a radial direction with respect to the commutator, and aninsulating member carried by said plunger and movable longitudinallytherewith and engaging the brush arm whereby said plunger is eiiiectiveto move said member for moving the brush to operative position uponenergization of said solenoid.

23. In a dynamo-e1eetric machine of the commutator type, a brush for thecommutator, an arm carrying said brush, means for yieldingly holdingsaid brush in inoperative position, a solenoid having a plunger operatedthereby in a radial direction with respect to the commutator, and amember carried by said plunger and movable longitudinally therewith andhaving a transverse portion engaging the brush arms whereby said plungeris effective to move said member for moving the brush to operativeposition upon energization of said solenoid.

24.. In a dynamo-electric machine of the commutator type, a brush forthe commutator, an arm carrying said brush, means for yieldingly holdingsaid brush in inoperative position, a solenoid having a plunger operatedthereby in a radial direction with respect to the commutator, and aninsulating'member carried by said plunger and movable longitudinallytherewith and having a transverse portion engaging the brush armswhereby said plunger is effective to move said member for moving thebrush to operative position upon energization of said solenoid.

25. In a dynamo-electric machine of the commutator type, a plurality ofbrushes for said commutator, pivotally mounted arms carrying saidbrushes at one end, respectively, and having their opposite endsadjacent each other in relatively close spaced relation, means foryieldingly holding said brushes in inoperative position, a solenoidhavin a plunger operated thereby in a radial direction with respect tosaid commutator, and means carried by the end of the plunger betweensaid arms and engaging the latter for moving said brushes intoengagement with the commutator upon energization of the solenoid.

26. In combination, a brush holder comprising an arm having meansthereon for pivotally mounting the same in cooperative relation with acommutator of a dynamo-electric machine, a brushreceiving member at oneend of said arm into which a brush is adapted to be inserted, a brush insaid member and having a recess therein at the top thereof, and a springsecured to said arm and having one end seated in the recess of the brushto provide resiliency thereto upon engagement thereof with a commutator.

2'7. In combination, a brush holder comprising an arm having meansthereon for pivotally mounting the same in cooperative relation with acommutator of a dynamo-electric machine, a brushreceiving member at oneend of said arm into which a brush is adapted to be inserted, a brush insaid member and having a recess therein at the top thereof, and a springsecured tosaid arm and having one end seated in the recess of the brushto provide resiliency thereto upon engagement thereof with a commutator,said spring being pivoted on said arm so that upon having its end liftedout of the recess in the brush it may be moved laterally to one side orthe other of the brush to facilitate the insertion and removal of saidbrush.

28. In combination, a brush holder comprising an arm having meansthereon for pivotally mounting the same in cooperative relation with acommutator of a dynamo-electric machine, a brushreceiving member at oneend of said arm into which a brush is adapted tobe inserted, a brush insaid member having an upper enlarged portion to prevent said brush frompassing through said member and having a recess therein at the topthereof, and a spring secured to said arm and having one end seated inthe recess of the brush to provide resiliency thereto upon engagementthereof with a commutator.

29. In combination, a brush holder comprising an arm having meansthereon for pivotally mounting the same in cooperative relation with acommutator of a dynamo-electric machine, a sleeve at one end of said arminto which a brush is adapted to be inserted, a brush in said sleeve andhaving a recess therein at the top thereof, and a spring secured to saidarm and having one end seated in the recess of the brush to provideresiliency thereto.

30. In combination, a brush holder comprising an arm having meansthereon for pivotally mounting the same in cooperative relation with acommutator of a dynamo-electric machine, a sleeve at one end of said arminto which a brush is adapted to be inserted, a brush in said sleeve andhaving a recess therein at the top thereof, and a spring secured to saidarm and having one end seated in the recess of the brush to provideresiliency thereto, said spring being pivoted on said arm so that uponhaving its end lifted out of the recess of the brush it may be movedlaterally to one side or the other of the brush to facilitate theinsertion and removal of said brush.

31. In combination, a brush holder comprising an arm, a brush receivingmember at one end of said arm into which a brush is adapted to beinserted, a brush in said member, a spring pivotally secured to said armfor lateral movement with respect thereto and having one end engagingthe brush to hold the latter in said member and to provide resiliencythereto when engaging a commutator, and means on said brush forautomatically locking the spring in engaged position with the brush uponsaid spring being brought into engagement therewith.

32. In a dynamo-electric machine of the commutator type, a brush for thecommutator, an arm carrying said brush, means for yieldingly holdingsaid brush in inoperative position, a solenoid having a plunger operatedthereby along a radial line of the commutator, a member engaging saidarm, and a yielding connection between said plunger and said member formoving said brush to operative position.

33. In a dynamo-electric machine, a brush holder, a brush, electricalmeans for moving said brush into operative position, resilient means foropposing said movement of the brush, and another resilient meanspivotally mounted on the brush holder for holding the brush therein andfor preventing shock to the brush upon its being moved into operativeposition.

" CHARLES I. McNEIL.

